Nature, culture and history

Natural environment

Moreton Bay Marine Park protects a vast array of marine habitats, plants and animals. Covering more than 3400km2 of open and sheltered waterways and dotted with islands, Moreton Bay Marine Park includes some of Australia's premier wetlands. Extensive mangroves and tidal flats support and shelter fish, birds and other wildlife. Sandflats provide roosting sites for migratory birds and seagrass beds nurture fish, shellfish, dugong and turtles.

Moreton Bay wetlands

In 1971, in the Iranian city of Ramsar, representatives from 18 nations signed the Convention on Wetlands of International Significance (known as the Ramsar Convention) to stop global loss of wetlands, and to conserve and sustainably manage remaining wetlands. Moreton Bay is one of Australia's largest sites listed under the Ramsar Convention.

The wetlands of Moreton Bay are extremely varied and range from perched freshwater lakes and sedge swamps on the offshore islands, to intertidal mudflats, marshes, sandflats and mangroves adjoining the bay's islands and the mainland. This variety in habitats contributes to the bay's biological diversity. The high diversity is also due to the location and climate of the bay; it supports tropical, subtropical and temperate wildlife species.

Seagrasses and mangroves

The seagrass beds, mudflats and mangroves of Moreton Bay Marine Park provide food and habitat for a wide variety of marine life.

Seagrasses are flowering plants. Their closest relatives are lilies and orchids. Seagrasses need sunlight, clear water and nutrients—often obtained from nearby mangroves—to grow. The seagrasses between Russell Island and North Stradbroke Island and in southern Moreton Bay provide food and habitat for dugong, turtles, fish and crustaceans.

Mangroves provide a nursery for fish, prawns and crabs, which form the basis of an important commercial and recreational fishery. Mangrove communities act as stabilisers, helping to reduce excessive sediment flow and decreasing the threat of erosion caused by currents and stream flow. Seven species of mangroves are found in the marine park.

Dugong

DugongDugong dugon, also known as sea cows, can grow to about 3m long and weigh up to 400kg. Adult dugong feed predominantly on seagrass and can consume 30kg per day. As they feed, whole plants are uprooted and a tell-tale feeding trail is left. The female dugong takes up to 17 years to mature and then only produces one young every five years if the conditions are suitable. Dugong are listed as a vulnerable species under the Nature Conservation Act 1992.

Whales

The humpback whale Megaptera novaeangliae is the fifth largest of the great whales. Adult females grow to 15m, slightly longer than males. A mature humpback can weigh 40t. Humpbacks are generally blackish with white underbellies and sides. They are listed as a vulnerable species under the Nature Conservation Act 1992.

Humpbacks mate and give birth in warmer waters. Each year the east Australian humpback whale population migrates 6000km, from their Antarctic feeding grounds, along the eastern coastline of Australia, to arrive in the lagoons of the Great Barrier Reef in about mid-June. From July, after calving, the humpbacks start to migrate south—back to the Antarctic waters. A proportion of the population stops over in Moreton Bay. Most humpbacks have left Queensland waters by early November.

Dolphins

Bottlenose dolphins are the largest of the beaked dolphins and have a short, stout beak (sometimes described as bottle-shaped) marked with a crease where it meets the forehead. Their average size is about 3m and they feed on invertebrates, bottom-dwelling fish and squid, plus the full range of pelagic fish species. In bays they form small groups of about 15 individuals, while groups offshore may number in the hundreds. A single calf is born after a gestation period of about a year. Bottlenose dolphins have a life span of up to 45 years.

Indo-Pacific hump-backed dolphins are a coastal species found in tropical and subtropical waters. In Queensland they are found in Moreton Bay and its adjacent waters and in Tin Can Inlet, Great Sandy Strait. Body colour ranges from white to pinkish to grey, with some individuals being heavily spotted. They grow to a length of about 2.7m and the beak is long and cylindrical. Indo-Pacific hump-backed dolphins feed in shallow waters and have a varied diet of fish, molluscs and crustaceans. Indo-Pacific hump-backed dolphins are listed as rare under the Nature Conservation Act 1992.

Green turtles have an olive-green carapace (shell) and a relatively small head compared with the size of its body. Young green turtles are carnivorous, eating tiny marine animals, yet the adults are thought to be totally herbivorous, feeding on algae, seagrass and mangrove fruits. Females take 30 to 50 years to mature and only breed every two to eight years. Green turtles are listed as vulnerable under the Nature Conservation Act 1992.

Loggerhead turtles are listed as endangered under the Nature Conservation Act 1992. The carapace is dark brown, sometimes irregularly speckled with a darker brown. They occur in coral reefs, bays and estuaries in tropical and warm temperate waters off the coast of Queensland, Northern Territory, Western Australia and New South Wales. Loggerhead turtles are carnivorous, feeding mostly on shellfish, crabs, sea urchins and jellyfish.

Hawksbill turtles occur in tidal and sub-tidal coral and rocky reef habitats through tropical waters, extending into warm temperate areas as far south as northern New South Wales. The carapace is heart-shaped and olive-green to brown, richly variegated with reddish-brown, dark brown and black. Hawksbill turtles are omnivores, feeding on sponges, seagrasses, algae, soft corals and shellfish. Hawksbill turtles are listed as vulnerable under the Nature Conservation Act 1992.

Most of the shorebird species which visit Moreton Bay Marine Park's intertidal flats are migratory species listed under the Japan Australia Migratory Bird Agreement (JAMBA) or the China Australia Migratory Bird Agreement (CAMBA).

Most migrate from Arctic or sub-Arctic regions at the end of the breeding season, moving to the southern hemisphere and stopping to rest before the next stage of their long journey. When feeding here, migratory shorebirds are storing energy for their return trip north to breed again.

The migratory shorebirds prefer four main habitats—muddy intertidal flats with and without seagrass, sandy flats and coral rubble on islands in the middle of the bay. Mirapool sandflat, in the south-east of Moreton Island, is considered a vital roosting and feeding site for waders, particularly eastern curlews.

Major roosting and feeding sites for shorebirds include open sandy islands and beaches (mainly on Moreton Island and North Stradbroke Island), saltpans and claypans scattered in and behind the mangrove fringe, freshwater marshes and mangroves.

Resident shorebirds

Moreton Bay has about 3500 resident shorebirds, representing 10 species. These birds breed in and around Moreton Bay. Some of the most recognisable species include the pied oystercatcher, the bush stone-curlew and the red-capped plover. The beach stone-curlew and the sooty oystercatcher are less common and are of international and national significance because ongoing disturbance has drastically reduced their numbers.

When it is time for resident shorebirds to breed, they build their simple nests just above the high-tide line of beaches and rocky shorelines. For this reason they are vulnerable to damage from vehicles driving above high tide lines and from people camping on undisturbed foredunes. Each year, many young shorebirds and some adults are killed due to beach traffic.